How to install ALSA EQUALIZER on Volumio 2 with HiFiBerry

[Update] Before you start setting up the equalizer like I described here, have a look at the one Balbuze wrote as a very simple to use and perfect plugin: https://github.com/balbuze/volumio-plugins/tree/master/plugins/miscellanea/volsimpleequal

Step 1:

Update the system

sudo apt-get update -y

Step 2:

Install the alsaeq modules

sudo apt-get install -y libasound2-plugin-equal

Step 3:

Detect the device number of your sound card

aplay -l

Raspberry pi with HiFiBerry

Step 4:

Set the mixer type to hardware

Step 5:

Configure asound.conf

cd /etc
sudo nano -w asound.conf

Paste this into the new file or add it at the end, if volumio already created that file.

ctl.equal {
  type equal;
}

pcm.plugequal {
  type equal;
  # Modify the line below if you don't
  # want to use sound card 0.
  slave.pcm "plughw:1,0";
  # or if you want to use with multiple applications output to dmix
  # slave.pcm "plug:dmix"
}

#pcm.equal {
  # Or if you want the equalizer to be your
  # default soundcard uncomment the following
  # line and comment the above line.
pcm.!default {
  type plug;
  slave.pcm plugequal;
}

Step 6:

Change the mpd configuration

cd /etc
sudo nano mpd.conf

Search for the device entry in the audio_output and comment the entry by adding a # at the beginning of the line. Create a new entry which sets the device to the EQUALIZER. "plug:plugequal"

# Audio Output ################################################################
audio_output {
  ...
                # device        "hw:1,0"
                device          "plug:plugequal" 
  ...  
}              

Setp 7:

Configure the mpd to use the EQUALIZER

sudo -H -u mpd alsamixer -D equal

Setp 8:

Reboot the system

Links:

This article tries to summaries to following links. I documents the way, it worked on my raspberry pi 3 with HiFiBerry. It didn't work on the same device with a Sound Blaster USB device instead of HiFiBerry.

https://support.hifiberry.com/hc/en-us/articles/205311292-Adding-equalization-using-alsaeq

https://volumio.org/forum/equalizer-t45.html

http://www.hifi-forum.de/viewthread-253-600.html

http://wiki.cyberleo.net/wiki/KnowledgeBase/AlsaEqual

https://volumio.org/forum/equalizer-t45.html

https://support.hifiberry.com/hc/en-us/community/posts/207226345-Problem-configuring-alsa-equalizer